U.S. patent application number 12/590446 was filed with the patent office on 2010-06-10 for cable.
This patent application is currently assigned to Lapp Engineering & Co.. Invention is credited to Siegbert Lapp.
Application Number | 20100142902 12/590446 |
Document ID | / |
Family ID | 39712199 |
Filed Date | 2010-06-10 |
United States Patent
Application |
20100142902 |
Kind Code |
A1 |
Lapp; Siegbert |
June 10, 2010 |
Cable
Abstract
In order to improve a cable, comprising an inner cable body, in
which at least one conductor strand of an optical and/or electrical
conductor runs in the longitudinal direction of the cable, an outer
cable sheath, enclosing the inner cable body and lying between an
outer sheath surface of the cable and the inner cable body, and at
least one information carrier unit, disposed within the outer
sheath surface of the cable such that the cable also comprises a
shielding, the invention proposes that the information carrier unit
having an antenna unit lying in an antenna surface running
approximately parallel to the longitudinal direction of the cable,
by the antenna surface running at a distance from an electrical
shielding of the cable and by providing, between the antenna
surface and the shielding, a spacing layer, in which the
electromagnetic field that couples to the antenna unit and passes
through the antenna surface can extend between the antenna unit and
the shielding.
Inventors: |
Lapp; Siegbert; (Stuttgart,
DE) |
Correspondence
Address: |
Lipsitz & McAllister, LLC
755 MAIN STREET
MONROE
CT
06468
US
|
Assignee: |
Lapp Engineering & Co.
Cham
CH
|
Family ID: |
39712199 |
Appl. No.: |
12/590446 |
Filed: |
November 6, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/EP2008/055229 |
Apr 29, 2008 |
|
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|
12590446 |
|
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Current U.S.
Class: |
385/101 ;
174/70R |
Current CPC
Class: |
H01B 7/368 20130101 |
Class at
Publication: |
385/101 ;
174/70.R |
International
Class: |
G02B 6/44 20060101
G02B006/44; H02G 3/00 20060101 H02G003/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 8, 2007 |
DE |
10 2007 022 325 |
Claims
1-70. (canceled)
71. Cable, comprising an inner cable body, in which at least one
conductor strand of an optical and/or electrical conductor runs in
the longitudinal direction of the cable, an outer cable sheath,
enclosing the inner cable body and lying between an outer sheath
surface of the cable and the inner cable body, and at least one
information carrier unit, disposed within the outer sheath surface
of the cable, the information carrier unit having an antenna unit
lying in an antenna surface that runs approximately parallel to the
longitudinal direction of the cable, the antenna surface running at
a distance from an electrical shielding of the cable and provided
between the antenna surface and the shielding, there is an
electrically non-conductive spacing layer, in which the
electromagnetic field that couples to the antenna unit and passes
through the antenna surface can extend between the antenna unit and
the shielding.
72. Cable according to claim 71, wherein the spacing layer is
formed at least partially such that it concentrates the magnetic
field that couples to the antenna unit.
73. Cable according to claim 72, wherein a
magnetic-field-concentrating layer is disposed in the spacing
layer.
74. Cable according to claim 73, wherein the
magnetic-field-concentrating layer comprises magnetically
conductive particles.
75. Cable according to claim 74, wherein the magnetically
conductive particles have a particle size in the range from
approximately 1 .mu.m to approximately 50 .mu.m.
76. Cable according to claim 74, wherein the magnetically
conductive particles are embedded in an embedding material.
77. Cable according to claim 76, wherein the embedding material
electrically insulates the magnetically conductive particles from
one another.
78. Cable according to claim 76, wherein the embedding material is
a plastic material.
79. Cable according to claim 72, wherein the
magnetic-field-concentrating layer faces the shielding with its
side that faces away from the antenna unit.
80. Cable according to claim 72, wherein the
magnetic-field-concentrating layer extends in an area of extent
running approximately parallel to the antenna surface.
81. Cable according to claim 80, wherein the
magnetic-field-concentrating layer has, in the area of extent, an
extent which corresponds at least to an extent of the antenna unit
in the antenna surface.
82. Cable according to claim 81, wherein the
magnetic-field-concentrating layer has, in the area of extent, an
extent which goes beyond the extent of the antenna unit in the
antenna surface.
83. Cable according to claim 72, wherein an intermediate layer is
disposed between the magnetic-field-concentrating layer and the
antenna unit.
84. Cable according to claim 83, wherein the intermediate layer is
of a magnetically inert material.
85. Cable according to claim 71, wherein the antenna unit is
disposed on a base.
86. Cable according to claim 85, wherein the base is produced from
a magnetically inert material.
87. Cable according to claim 85, wherein the base forms the
intermediate layer between the antenna unit and the
magnetic-field-concentrating layer.
88. Cable according to claim 71, wherein the antenna unit is
disposed on a carrier strand and the magnetic-field-concentrating
layer is disposed on the carrier strand.
89. Cable according to claim 88, wherein the
magnetic-field-concentrating layer is disposed on a side of the
carrier strand that faces the antenna unit.
90. Cable according to claim 71, wherein the spacing layer is at
least partly formed by an intermediate sheath lying between the
shielding and the outer cable sheath.
91. Cable according to claim 90, wherein the intermediate sheath
comprises the magnetic-field-concentrating layer.
92. Cable according to claim 91, wherein magnetically conductive
particles are disposed on the intermediate sheath.
93. Cable according to claim 91, wherein magnetically conductive
particles are embedded in the surface in the intermediate
sheath.
94. Cable according to claim 90, wherein the antenna unit is
disposed on an intermediate sheath lying between the shielding and
an outer cable sheath.
Description
[0001] This application is a continuation of International
application No. PCT/EP2008/055229 filed on Apr. 29, 2008.
[0002] This patent application claims the benefit of International
application No. PCT/EP2008/055229 of Apr. 29, 2008 and German
application No. 10 2007 022 325.2 of May 8, 2007, the teachings and
disclosure of which are hereby incorporated in their entirety by
reference thereto.
BACKGROUND OF THE INVENTION
[0003] The invention relates to a cable, comprising an inner cable
body, in which at least one conductor strand of an optical and/or
electrical conductor runs in the longitudinal direction of the
cable, an outer cable sheath, enclosing the inner cable body and
lying between an outer sheath surface of the cable and the inner
cable body, and at least one information carrier unit, disposed
within the outer sheath surface of the cable.
[0004] Such cables are known from the prior art. In the case of
these known solutions, however, the inner cable body is not
shielded by a shielding in the cable.
[0005] It is therefore an object of the invention to improve a
cable of the type described at the beginning in such a way that it
also has a shielding.
SUMMARY OF THE INVENTION
[0006] This object is achieved according to the invention in the
case of a cable of the type described at the beginning by the
information carrier unit having an antenna unit lying in an antenna
surface running approximately parallel to the longitudinal
direction of the cable, by the antenna surface running at a
distance from an electrical shielding of the cable and by
providing, between the antenna surface and the shielding, a spacing
layer, in which the electromagnetic field that couples to the
antenna unit and passes through the antenna surface can extend
between the antenna unit and the shielding.
[0007] The advantage of the solution according to the invention can
be seen in that, by the spacing layer provided, it created the
possibility of also achieving, when a shielding is present, a
coupling of the antenna unit to the antenna unit of a read/write
device.
[0008] In order to improve the formation of the electromagnetic
field between the antenna unit and the shield, it is preferably
provided that the spacing layer is formed in an electrically
nonconducting manner.
[0009] It is particularly advantageous in this respect if the
spacing layer is formed such that it does not influence the
electromagnetic field that couples to the antenna unit.
[0010] It is preferably provided in this respect that the antenna
unit is disposed at a distance of at least 1.5 mm from the
shielding.
[0011] It is still better if the antenna unit is disposed at a
distance of at least 2 mm from the screen.
[0012] As an alternative to the solution that the spacing layer is
formed such that it does not influence the electromagnetic field
that couples to the antenna unit, another solution provides that
the spacing layer is formed at least partially such that it
concentrates the magnetic field that couples to the antenna unit.
Such a form of the spacing layer has the advantage that, by the
concentration of the electromagnetic field, it opens up the
possibility of achieving a good coupling between the antenna unit
of the information carrier unit and the antenna unit of a
read/write device even when there are small distances between the
antenna unit and the shielding, since the field concentration has
the effect that the electromagnetic field does not reach the
shielding, and consequently no eddy currents weakening the
electromagnetic field can be induced in said shielding.
[0013] It is particularly advantageous in this respect if a
magnetic-field-concentrating layer is disposed in the spacing
layer.
[0014] Such a magnetic-field-concentrating layer usually has a
thickness of less than approximately 2 mm, and can consequently be
provided without appreciably influencing the geometry of the
cable.
[0015] Such a magnetic-field-concentrating layer can be produced
particularly advantageously if it comprises magnetically conductive
particles.
[0016] Such magnetically conductive particles are, for example,
particles of ferrite, in particular magnetite, or of metal
alloys.
[0017] Such magnetically conductive particles preferably have a
particle size in the range from approximately 1 .mu.m to
approximately 50 .mu.m, preferably in the range between
approximately 2 .mu.m and approximately 20 .mu.m.
[0018] Furthermore, the magnetically conductive particles are
suitably formed in an electrically nonconducting manner, so that
they do not change the insulating properties in the cable, as is
the case with ferrite.
[0019] The magnetically conductive particles can be disposed in the
layer in a very wide variety of ways. For example, the magnetically
conductive particles could be disposed on the surface of the
shielding.
[0020] A particularly advantageous and lastingly viable solution
provides that the magnetically conductive particles are embedded in
an embedding material.
[0021] In particular in the case of electrically conductive
particles, the embedding material suitably has the effect that the
magnetically conductive particles are electrically insulated from
one another, in order to avoid eddy current effects. This can be
achieved in the simplest case by an embedding material which is
itself electrically nonconducting.
[0022] In particular in order not to impair the mechanical
properties of the cable, such an embedding material is a plastics
material.
[0023] It is preferably provided in this respect that the plastics
material is either a thermosetting or thermoplastic material, or
for example PVC.
[0024] No further details have been specified so far with respect
to the way in which the magnetic-field-concentrating layer is
aligned and disposed.
[0025] It is particularly advantageous if the side of the
magnetic-field-concentrating layer that faces away from the antenna
unit, faces the shielding.
[0026] In this case, the magnetic-field-concentrating layer
preferably runs over the entire extent of the antenna unit between
the latter and the shielding.
[0027] With regard to the thickness of the
magnetic-field-concentrating layer, no further details have been
specified so far. An advantageous solution provides that the
magnetic-field-concentrating layer has a thickness from
approximately 50 .mu.m to approximately 2 mm.
[0028] In order to obtain the same advantageous effects of the
magnetic-field-concentrating layer in the entire region of the
antenna unit, it is preferably provided that the
magnetic-field-concentrating layer extends in an area of extent
running approximately parallel to the antenna surface.
[0029] In principle, the magnetic-field-concentrating layer could
in this case have a smaller extent than the antenna unit in the
antenna surface. It is particularly advantageous, however, if the
magnetic-field-concentrating layer has, in the area of extent, an
extent which corresponds at least to an extent of the antenna unit
in the antenna surface.
[0030] It is still better if the magnetic-field-concentrating layer
has, in the area of extent, an extent which goes beyond the extent
of the antenna unit in the antenna surface.
[0031] It is particularly advantageous for the formation of the
magnetic field if a projection of the antenna unit lying in the
antenna surface onto the area of extent of the
magnetic-field-concentrating layer is disposed such that it is
approximately centered in relation to the extent of this layer in
the area of extent, so that the magnetic-field-concentrating layer
acts in the same way substantially in opposite directions in each
case with regard to its effect in relation to the antenna unit.
[0032] With regard to the extent of the antenna surface, no further
details have been specified so far. It would, for example, be
conceivable for the antenna surface to run in a substantially
planar manner, if it does not have a particularly great extent
transversely to the longitudinal direction of the cable.
[0033] It is more advantageous, however, if the antenna surface is
adapted to the cable geometry and runs in an approximately
cylindrical manner with respect to a center axis of the cable.
[0034] Purely in principle, it would also be conceivable for the
area of extent for the magnetic-field-concentrating layer to run in
a substantially planar manner. It is still more advantageous if the
area of extent for the magnetic-field-concentrating layer also runs
in a curved manner.
[0035] It is still more advantageous in this respect if the area of
extent runs in an approximately cylindrical manner with respect to
a center axis of the cable.
[0036] In order to improve further the effect of the
magnetic-field-concentrating layer on the antenna unit, it is
preferably provided that an intermediate layer is disposed between
the magnetic-field-concentrating layer and the antenna unit.
[0037] This intermediate layer is preferably formed from a
magnetically inert material.
[0038] With regard to the way in which the antenna unit is formed
or the way in which it is realized, no further details have been
specified so far.
[0039] For example, the antenna unit could be formed in a
self-supporting manner.
[0040] A particularly advantageous solution, however, provides that
the antenna unit is disposed on a base.
[0041] In order also not to obtain any impairment of the coupling
by way of the magnetic field from the base, it is preferably
provided that the base is produced from a magnetically inert
material.
[0042] For example, the base could be formed such that it forms the
intermediate layer.
[0043] In order also to be easily able to introduce the antenna
into the cable and position it in a defined manner, it is
preferably provided that the antenna is disposed on a carrier
strand.
[0044] Furthermore, it is likewise preferably provided that the
magnetic-field-concentrating layer is disposed on the carrier
strand, so that it is consequently easily possible to position both
the antenna unit and the magnetic-field-concentrating layer in
relation to each other.
[0045] In order in the case of a carrier strand to obtain as little
disturbance as possible of the mechanical properties of the cable,
it is preferably provided that the magnetic-field-concentrating
layer is disposed on a side of the carrier strand that faces the
antenna unit, so that both the antenna unit and the
magnetic-field-concentrating layer lie on the same side of the
carrier strand.
[0046] With regard to the extent of the carrier strand, no further
details in this respect have been specified in the matter discussed
so far.
[0047] An advantageous solution thus provides that the carrier
strand runs approximately parallel to a longitudinal direction of
the shielding.
[0048] In this case, it is conceivable, for example, for the
carrier strand to be formed as a filler tape, which is formed such
that it encloses the shielding in the circumferential
direction.
[0049] Another advantageous solution provides that the carrier
strand runs such that it wraps around the shielding.
[0050] The carrier strand is preferably formed in this case such
that it winds around the shielding.
[0051] In this case, a further separating layer could also lie
between the carrier strand and the shielding. It is particularly
advantageous, however, if the carrier strand lies directly on the
shielding.
[0052] In the case of one embodiment, the carrier strand is formed
in such a way that it merely serves the purpose of holding the
information carrier unit and positioning it in the cable.
[0053] The carrier strand may, however, also have further
functions. For example, the carrier strand is formed at least as
part of a separating layer between the shielding and the cable
sheath.
[0054] As an alternative to this, however, it is also conceivable
for the carrier strand to lie on a separating layer between the
shielding and the outer sheath of the cable.
[0055] A further advantageous solution provides that the antenna
unit of the information carrier unit is disposed on a side of the
carrier strand that faces away from the shielding, so that as a
result no impairment of the mechanical properties of the cable can
occur, in particular the relative movement between the shielding
and the part of the cable surrounding said shielding.
[0056] Another solution which does not impair the mechanical
properties of the cable provides that the antenna unit is embedded
in the carrier strand.
[0057] A further advantageous solution provides that the spacing
layer is at least partly formed by an intermediate sheath lying
between the shielding and the outer sheath of the cable.
[0058] This intermediate sheath creates many advantageous
possibilities with regard to the structure of a cable according to
the invention.
[0059] For example, such an intermediate sheath creates the
possibility of compensating for the surface undulations, in
particular variations in radius, which are caused by the twisting
of the conductor strands and by the form of the surface deviating
from a substantially cylindrical form and are also manifested on
structures lying on the inner cable body, and of consequently
creating advantageous preconditions for supporting or accommodating
the information carrier unit as uniformly as possible and
substantially compensating for the surface undulations.
[0060] In the case of an advantageous embodiment, it is provided
that the intermediate sheath between the information carrier unit
and the shielding around the inner cable body has a material layer
compensating for surface undulations of the inner cable body.
[0061] There is consequently the possibility of integrating
information carrier units, in particular those that are locally
pressure-sensitive, into the cable, since the material layer
substantially prevents compressive forces which are locally unequal
due to the surface undulations from acting on the information
carrier unit, in particular during bending of the cable.
[0062] Furthermore, it is provided in the case of an advantageous
embodiment that the intermediate sheath forms a surface which is
substantially free from surface undulations of the inner cable
body, so that a supporting surface that avoids mechanical loading
is available for the information carrier unit.
[0063] It is of advantage in this respect if the intermediate
sheath has a substantially smooth, ideally even substantially
cylindrical, surface for the information carrier unit.
[0064] In addition, such an intermediate sheath provides the
advantage of easily forming the spacing layer between the screen
and the antenna surface with the greatest possible thickness.
[0065] Furthermore, such an intermediate sheath can also be
advantageously used in such a way that the intermediate sheath
comprises the magnetic-field-concentrating layer.
[0066] Such a magnetic-field-concentrating layer could be produced,
for example, by magnetically conductive particles distributed in
the intermediate sheath.
[0067] Since this layer can generally be relatively thin, it is
preferably provided that magnetically conductive particles are
disposed on the intermediate sheath.
[0068] In order, however, to be able to make the
magnetic-field-concentrating layer thin, it is preferably provided
that magnetically conductive particles are disposed on a surface of
the intermediate sheath.
[0069] In this case, the surface of the intermediate sheath may be
that which faces the shield, or that which faces the outer sheath
of the cable.
[0070] In particular, it is advantageous if magnetically conductive
particles are embedded in the surface in the intermediate
sheath.
[0071] Such magnetically conductive particles can be easily
embedded in the surface in a still soft material of the
intermediate sheath, for example, by dusting or powdering or
sprinkling.
[0072] This can be achieved, for example, by the shielding being
provided with the magnetically conductive particles and then the
intermediate sheath extruded on top. As an alternative to this, it
is provided that the magnetically conductive particles are applied
to the extruded-on intermediate sheath.
[0073] With regard to the way in which the antenna unit is
disposed, likewise no further details have been specified so far.
An advantageous solution provides that the antenna unit is disposed
on an intermediate sheath lying between the shielding and an outer
sheath of the cable.
[0074] The antenna unit could be disposed in such a way by, for
example, the antenna unit being fully integrated in the
intermediate sheath.
[0075] However, a solution which can be easily realized provides
that the antenna unit is disposed on a surface of the intermediate
sheath. In this case, the antenna unit can be provided particularly
easily on the intermediate sheath when the cable is being
produced.
[0076] It is particularly easy in this respect if the antenna unit
is disposed on the surface of the intermediate sheath.
[0077] In order to achieve good fixing of the antenna unit, it is
provided in the case of an alternative embodiment that the antenna
unit is at least partly embedded into the intermediate sheath.
[0078] Such partial embedding of the antenna unit in the
intermediate sheath may likewise be performed by embedding a wire.
For example, if the antenna unit is a simple loop.
[0079] However, it is also conceivable to realize embedding of a
conductor track, formed by a conductive paste or a conductive
lacquer.
[0080] It is still more advantageous, in particular for the
protection of the antenna unit, if the latter is predominantly
embedded in the intermediate sheath.
[0081] The protection is particularly good if the antenna unit is
substantially embedded in the intermediate sheath.
[0082] As already mentioned, there are various advantageous
embodiments of the antenna unit. An advantageous embodiment
provides that the antenna unit is formed by an antenna wire.
[0083] Such an antenna wire may, for example, be laid as such onto
the surface of the intermediate sheath and connected to the
integrated circuit.
[0084] However, there is also the possibility of embedding the
antenna wire partially or largely or completely in the intermediate
sheath.
[0085] Another suitable embodiment of the antenna unit provides
that it is formed as a conductor track on a base.
[0086] Such a formation of the antenna unit as a conductor track on
a base has the advantage that the conductor track on the base can
be produced in advance and then can be disposed together with the
base on the intermediate sheath. In this case, the integrated
circuit may likewise be disposed on the base.
[0087] There is also the possibility of disposing the integrated
circuit on the intermediate sheath in advance and subsequently
disposing the antenna unit with the base on the intermediate
sheath.
[0088] A further advantageous possibility also envisages first
disposing the antenna unit with the base on the intermediate sheath
and then placing the intermediate circuit on it.
[0089] With regard to how the base is disposed in relation to the
surface of the intermediate sheath, an advantageous solution
provides that the base lies on the surface of the intermediate
sheath.
[0090] This can be realized by the base being on the surface of the
intermediate sheath.
[0091] It is alternatively conceivable for the base to be at least
partly embedded in the intermediate sheath. It is still better if
the base is predominantly embedded in the intermediate sheath and a
particularly suitable solution for the protection of the base
provides that the base is substantially embedded in the
intermediate sheath.
[0092] Another advantageous embodiment of the antenna unit provides
that the antenna unit is formed as a conductor track disposed
directly on the intermediate sheath. Forming the conductor track in
such a way makes it possible for the intermediate sheath itself to
be used directly as a base.
[0093] In this case, the conductor track may, for example, be
formed by a conductive material applied to the intermediate
sheath.
[0094] The conductive material may in this case be disposed
directly on the surface of the intermediate sheath, and
consequently be merely on the surface of the same and be covered by
the outer sheath.
[0095] Better fixing of the conductor track envisages that the
conductor track is at least partially embedded in the intermediate
sheath.
[0096] It is still better in this respect for the conductor track
to be largely or substantially completely embedded in the
intermediate sheath, since this makes it possible, in particular
when an electrically conductive material is applied, to achieve
better protection of the same and also better protection of the
contacting between the same and the integrated circuit.
[0097] A particularly advantageous embodiment provides that the
conductor track is applied to the intermediate sheath by a printing
operation or impressing operation.
[0098] When explaining the information carrier unit itself, no
further details have been specified so far. An advantageous
solution provides that the information carrier unit comprises an
integrated circuit.
[0099] This integrated circuit may also be initially disposed in
principle at any location in the cable.
[0100] A particularly advantageous solution provides in this
respect that the integrated circuit is combined with the antenna
unit to form a subassembly.
[0101] In this case, it is likewise advantageous if the integrated
circuit is disposed on the intermediate sheath.
[0102] It is still better if the integrated circuit is at least
partly embedded in the intermediate sheath.
[0103] A particularly suitable solution provides that the
integrated circuit is at least partly embedded in the outer sheath
of the cable.
[0104] In the case of one embodiment of the information carrier
unit, when the integrated circuit is placed onto the conductor
tracks which form the antenna unit and are, for example, disposed
on the intermediate sheath, contacting between connecting points of
the integrated circuit and the conductor tracks takes place at the
same time, for example by an electrically conductive adhesive. For
this reason, the integrated circuit protrudes above the conductor
tracks.
[0105] In the case of such an exemplary embodiment, it may
therefore be of advantage if the integrated circuit stands above
the surface of the intermediate sheath and is at least partly
embedded in the outer sheath.
[0106] In the case of one embodiment, it is conceivable for the
integrated circuit to be substantially embedded in the outer
sheath.
[0107] With regard to the structure of the information carrier
units, no further details have been specified so far.
[0108] An advantageous solution provides that the information
carrier unit has at least one memory for the information that can
be read out.
[0109] Such a memory could be formed in a very wide variety of
ways. For example, the memory could be formed such that the
information stored in it can be overwritten by the read/write
device.
[0110] However, a particularly advantageous solution provides that
the memory has a memory area in which items of information once
written are stored such that they are write-protected.
[0111] Such a memory area is suitable, for example, for storing an
identification code for the information carrier unit or other data
specific to this information carrier unit, which can no longer be
changed by any of the users.
[0112] Such a memory area is also suitable, however, for the cable
manufacturer to store information which is not to be overwritten.
Such information is, for example, cable data, cable specifications
or else details of the type of cable and how it can be used.
[0113] However, these data may, for example, also be supplemented
by data comprising details about the manufacture of the specific
cable or data representing the test records from final testing of
the cable.
[0114] In addition, a memory according to the invention may also be
formed furthermore in such a way that it has a memory area in which
items of information are stored such that they are write-protected
by an access code.
[0115] Such write-protected storage of information may, for
example, comprise data which can be stored by a user. For example,
after preparation of the cable, a user could store in the memory
area data concerning the preparation of the cable or concerning the
overall length of the cable or concerning the respective portions
over the length of the cable, the user being provided for this
purpose with an access code by the cable manufacturer, in order to
store these data in the memory area.
[0116] A further advantageous embodiment provides that the memory
has a memory area to which information can be freely written.
[0117] Such a memory area may, for example, receive information
which is to be stored by the cable user in the cable, for example
concerning the type of installation or the preparation of the
same.
[0118] In particular when a number of information carrier units are
used, it would be conceivable, for example, for it to be possible
for all the information carrier units to be addressed with one
access code. However, this has the disadvantage that the
information carrier units consequently cannot be selectively used,
for example to assign different information to specific portions of
the cable.
[0119] One conceivable solution for assigning different information
to different portions of the cable would be that each of the
information carrier units bears a different specified length, so
that, by reading out the specified length of an information carrier
unit, its distance from one of the ends of the cable or from both
ends of the cable can be determined.
[0120] For this reason, it is advantageous if each of the
information carrier units can be individually addressed by an
access code.
[0121] In connection with the description so far of the information
carrier units, it has just been assumed that they carry information
which has been stored in the information carrier units by external
read/write devices either before or during the production of the
cable or during the use of the cable.
[0122] A further advantageous solution for a cable according to the
invention provides that the at least one information carrier unit
of the cable picks up at least one measured value of an associated
sensor, that is to say that the information carrier unit not only
stores and makes available external information but is itself
capable of acquiring information about the cable, that is to say
physical state variables of the cable.
[0123] The advantage of this solution can be seen in that it
enables the information carrier unit not only to be used for making
information available for reading out but also to be used for
providing by means of the sensor, indications about the state of
the cable, for example about physical state variables of the
cable.
[0124] In particular, such sensing of state variables may take
place during the operation of the cable or else independently of
the operation of the cable.
[0125] Consequently, there is an optimum possibility of on the one
hand sensing the state of the cable without in-depth investigation
of the same and on the other hand of possibly checking the state of
the cable, in particular to the extent that potential damage to the
conductor strands when certain physical state variables occur can
be detected.
[0126] In principle, any desired state variables can be picked up
with such a sensor, that is to say in principle all state variables
for which sensors that can be installed in cables exist.
[0127] A preferred solution provides in this respect that the
sensor picks up at least one of the state variables that may lead
to the cable becoming damaged--for example if they act for a long
time or if certain values are exceeded--such as radiation,
temperature, tension, pressure, elongation and moisture.
[0128] With regard to the way in which the sensor is disposed, no
specific details have been given so far.
[0129] An advantageous solution provides that the sensor is
mechanically connected to a base of the antenna unit.
[0130] With regard to the operation of the information carrier unit
and the operation of the sensor on the part of the information
carrier unit, no further details have been specified so far. An
advantageous solution provides that the information carrier unit
reads out the sensor in the activated state.
[0131] This means that the information carrier unit has no power
supply of its own, but has to be activated by an external energy
supply.
[0132] One possibility for such activation is that the information
carrier unit can be activated by a read/write device.
[0133] Another advantageous solution provides that the information
carrier unit can be activated by a magnetic field of a current
flowing through the cable, the magnetic field passing through the
shielding.
[0134] This solution has the advantage that no activation of the
information carrier unit by the read/write device is required, but
rather an alternating magnetic field which provides sufficient
energy for the operation of the information carrier unit is
available independently of the read/write device, the information
carrier unit likewise picking up this energy by way of a suitable
antenna.
[0135] The current flowing through the cable may, for example, be a
current which is variable over time, as is used in the case of
drives supplied with pulse-width-modulated current.
[0136] The current flowing through the cable may be a current
flowing in a data line or a variable-frequency current, as is used
in control lines for synchronous motors.
[0137] However, it is also conceivable for the current to be a
conventional alternating current at a specific frequency, for
example including the power-line frequency.
[0138] Furthermore, it would be possible for two lines of the cable
to be connected in such a way that an electromagnetic field with
the standardized carrier frequency of the information carrier units
to be produced. This would have the advantage that no special
measures have to be taken for supplying energy to the information
carrier units.
[0139] In all these cases, the coupling-in of the energy takes
place inductively by way of the alternating electromagnetic field,
in particular of low frequency, produced by this alternating
current and penetrating through the shielding, into the antenna
unit of the information carrier unit.
[0140] In principle, it would be sufficient to form the information
carrier unit in such a way that it picks up the measured value and
then transmits it immediately to the read/write device.
[0141] In order, however, to be able to pick up different measured
values at different points in time, for example including during
the transmission of other kinds of information between the
read/write device and the information carrier unit, it is
preferably provided that the information carrier unit stores the at
least one measured value in a memory. In this way, the measured
value can be read out at any times desired, that is to say whenever
it is requested by the read/write device.
[0142] In particular, there is also the possibility in this respect
of then picking up measured values and making them accessible later
when the information carrier unit is not interacting with a
read/write device and is, for example, activated by an
electromagnetic field of a current flowing through the cable.
[0143] Since cables can be expected to have long service lives and
the picking up of measured values would then produce a high volume
of data, it is convenient to provide a reduction in the amount of
data.
[0144] One possibility for reducing the amount of data provides
that the information carrier unit only stores a measured value in
the memory area if it exceeds a threshold value.
[0145] This may take place, for example, by the information carrier
unit constantly picking up the measured values, but the information
carrier unit being prescribed a threshold value as from which the
measured values are stored, so that normal states are not stored
but only the measured values which do not correspond to a normal
state defined by the threshold value.
[0146] These measured values are then stored in the simplest case
as nothing more than measured values, in somewhat more complex
cases as measured values with an indication of the time at which
they were picked up, or with an indication of other circumstances
in which these measured values were picked up.
[0147] As an alternative to this, an advantageous solution provides
that the information carrier unit only stores in the memory area,
measured values which lie outside a statistically determined normal
measured value distribution.
[0148] With regard to the regions in which the state variables are
determined by means of the sensor, no further details have been
specified so far.
[0149] One suitable solution provides that the sensor picks up at
least one state variable in the outer sheath of the cable, it being
possible for this to be, for example, radiation, temperature,
pressure, tension or elongation.
[0150] Another advantageous solution provides that the sensor picks
up state variables between the shielding and the outer sheath of
the cable.
[0151] For example, it is possible with such a solution to pick up
relative movements between the shielding and the outer sheath of
the cable.
[0152] These relative movements may reach an order of magnitude
which causes irreversible damage to the cable and, for example, an
increase in the friction between the screen and the outer sheath of
the cable.
[0153] For example, these excessive relative movements may lead to
a separating layer between the shielding and the outer sheath of
the cable becoming damaged or the shielding becoming damaged.
[0154] These relative movements may, however, also occur as
shearing stresses between the shielding and the outer sheath of the
cable and be picked up as such by a shearing force sensor.
[0155] With regard to the way in which the sensor is formed, no
further details have been specified so far.
[0156] It is advantageous if the sensor is a sensor which varies an
electrical resistance in accordance with the physical state
variable to be picked up, since an electrical resistance can be
easily picked up.
[0157] An alternative or additional solution provides that the
sensor is a sensor which varies a capacitance in accordance with
the physical state variable to be measured, since capacitance can
be easily picked up without great electrical power consumption.
[0158] Such a sensor can be realized particularly easily and at low
cost by a layer structure, in particular a multilayer structure,
since layer structures can be easily produced and easily adapted to
the respective conditions.
[0159] With regard to the way in which the sensor is disposed in
relation to the information carrier unit, furthermore, no further
details have been specified.
[0160] One solution provides that the sensor is disposed outside an
integrated circuit of the information carrier unit. This solution
makes it possible to use the sensor, for example, for picking up
tensile forces, shearing forces, elongations or excessive
elongations. However, it is also conceivable to use the sensor for
measuring radiation, temperatures or pressure at specific points of
the cable, for example in the inner cable body or in the separating
layer or in the cable sheath.
[0161] Such a solution makes it necessary, however, to produce and
maintain a stable and lasting electrical connection between the
sensor and the integrated circuit.
[0162] For these reasons, as an alternative to this, another
suitable solution provides that the sensor is disposed on the
integrated circuit. This solution has the advantage that the sensor
can be produced with the integrated circuit in a simple manner and
that far fewer problems occur in maintaining the sensor in working
order, since the sensor and the part of the integrated circuit
carrying it are fixedly connected to each other.
[0163] In the simplest case, the sensor may be provided as a
component of the integrated circuit that picks up a temperature in
the surroundings of the integrated circuit.
[0164] It is also conceivable, however, to form the sensor as a
moisture sensor, which picks up the moisture occurring in the
region of the integrated circuit.
[0165] With regard to the type of sensor and the way in which it is
formed, no further details have been specified so far.
[0166] An advantageous exemplary embodiment provides that the
sensor is a sensor which reacts irreversibly to the state variable
to be picked up.
[0167] Such a sensor has the advantage that it reacts irreversibly
when the state variable occurs, so that it is not necessary for the
sensor, and in particular the information carrier unit, to be
active at the point in time of the occurrence of the state variable
to be picked up or the occurrence of the deviation in the state
variable to be picked up. Rather, the sensor is capable at all
later points in time of generating a measured value which
corresponds to the state variable that was achieved at some point
in time in the past.
[0168] As an alternative to this, it is provided that the sensor is
a sensor which reacts reversibly with regard to the state variable
to be picked up. In this case, it is necessary to activate the
sensor when the state variable to be picked up occurs or when there
is a change in the state variable to be picked up, in order to be
able to pick up the measured value corresponding to this state
variable.
[0169] Further features and advantages are the subject of the
following description and the pictorial representation of some
exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0170] FIG. 1 shows a schematic block diagram of a first exemplary
embodiment of an information carrier unit according to the
invention;
[0171] FIG. 2 shows a plan view of how the first exemplary
embodiment of the information carrier unit according to the
invention is realized;
[0172] FIG. 3 shows a block diagram similar to FIG. 1 of a second
exemplary embodiment of an information carrier unit according to
the invention;
[0173] FIG. 4 shows a plan view similar to FIG. 2 of how the second
exemplary embodiment of the information carrier unit according to
the invention is realized;
[0174] FIG. 5 shows a plan view similar to FIG. 4 of a variant of
the second exemplary embodiment of the information carrier unit
according to the invention;
[0175] FIG. 6 shows a block diagram similar to FIG. 1 of a third
exemplary embodiment of an information carrier unit according to
the invention;
[0176] FIG. 7 shows a plan view similar to FIG. 2 of how the third
exemplary embodiment of the information carrier unit according to
the invention is realized;
[0177] FIG. 8 shows a perspective representation of individual
parts of the structure of a first exemplary embodiment of a cable
according to the invention;
[0178] FIG. 9 shows a section through the first exemplary
embodiment in the region of the information carrier unit;
[0179] FIG. 10 shows an enlarged representation of the conditions
in the region of the information carrier unit shown in section in
FIG. 9;
[0180] FIG. 11 shows a perspective representation similar to FIG. 8
of a second exemplary embodiment of a cable according to the
invention;
[0181] FIG. 12 shows an enlarged representation similar to FIG. 10
of the second exemplary embodiment of the cable according to the
invention;
[0182] FIG. 13 shows a perspective representation similar to FIG. 8
of a third exemplary embodiment of a cable according to the
invention;
[0183] FIG. 14 shows a perspective representation similar to FIG. 8
of a fourth exemplary embodiment of a cable according to the
invention;
[0184] FIG. 15 shows a section similar to FIG. 9 through the fourth
exemplary embodiment of the cable according to the invention in the
region of the information carrier unit;
[0185] FIG. 16 shows a section similar to FIG. 9 through a fifth
exemplary embodiment of the cable according to the invention in the
region of the information carrier unit;
[0186] FIG. 17 shows a section similar to FIG. 9 through a sixth
exemplary embodiment of a cable according to the invention;
[0187] FIG. 18 shows a section similar to FIG. 9 through a seventh
exemplary embodiment of a cable according to the invention and
[0188] FIG. 19 shows a section similar to FIG. 9 through an eighth
exemplary embodiment of a cable according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0189] An exemplary embodiment of an information carrier unit 10 to
be used according to the invention and represented in FIG. 1
comprises a processor 12, to which a memory designated as a whole
by 14 is linked, the memory preferably being formed as an
EEPROM.
[0190] Also connected to the processor 12 is an analog part 16,
which interacts with an antenna unit 18.
[0191] when there is electromagnetic coupling of the antenna unit
18 to an antenna unit 19 of a read/write device designated as a
whole by 20, the analog part 16 is then capable on the one hand of
generating, with the required power, the electrical operating
voltage that is necessary for the operation of the processor 12 and
the memory 14, as well as the analog part 16 itself, and on the
other hand of making available to the processor 12 the information
signals transmitted by electromagnetic field coupling at a carrier
frequency or transmitting information signals generated by the
processor 12 by way of the antenna unit 18 to the read/write device
20.
[0192] A very wide variety of carrier frequency ranges are possible
thereby.
[0193] In an LF range of approximately 125 to approximately 135
kHz, the antenna unit 18 acts substantially as a second coil of a
transformer, formed by the antenna unit 18 and the antenna unit 19
of the read/write device 20, energy and information transmission
taking place substantially by way of the magnetic field.
[0194] In this frequency range, the range between the read/write
device 20 and the antenna unit 18 is low, that is to say that, for
example, the mobile read/write device 20 must be brought up very
close to the antenna unit 18, to within less than 10 cm.
[0195] In an HF range between approximately 13 and approximately 14
MHz, the antenna unit 18 likewise acts substantially as a coil,
good energy transmission with a sufficiently great range being
possible as before in the interaction between the antenna unit 18
and the read/write device 20, the distance being, for example, less
than 20 cm.
[0196] In the UHF range, the antenna unit 18 is formed as a dipole
antenna, so that, when the power supply to the information carrier
unit 10 does not take place by way of the mobile read/write device
20, a great range in the communication with the read/write device
20 can be realized, for example up to 3 m, the interaction between
the read/write device 20 and the antenna unit 18 taking place by
way of electromagnetic fields. The carrier frequencies are from
approximately 850 to approximately 950 MHz or from approximately 2
to approximately 3 GHz or from approximately 5 to approximately 6
GHz. When the power is supplied by the mobile read/write device 20,
the communication range is up to 50 cm.
[0197] Depending on the frequency range, therefore, the antenna
units 18 are also differently formed. In the LF range, the antenna
unit 18 is formed as a compact, for example wound, coil with an
extent which may even be less than 1 cm.sup.2. In the case of this
frequency range, it can be assumed that a shielding provided in the
cable has substantially no effect on the coupling between the
antenna unit 18 and the read/write device 20.
[0198] In the HF range, the antenna unit 18 is likewise formed as a
flat coil, which may also have a greater extent of the order of
several square centimeters.
[0199] In the UHF range, the antenna unit 18 is formed as a dipole
antenna of diverse configurations.
[0200] In the HF and UHF ranges, the presence of shielding in the
cable has effects on the coupling between the antenna unit 18 and
the read/write device 20.
[0201] The memory 14 interacting with the processor 12 is
preferably divided into a number of memory areas 22 to 28, which
can be written to in various ways.
[0202] For example, the memory area 22 is provided as a memory area
which can be written to by the manufacturer and, for example,
carries an identification code for the information carrier unit 10.
This identification code is written in the memory field 22 by the
manufacturer, and at the same time the memory area 22 is
write-protected.
[0203] The memory area 24 can, for example, be provided with write
protection which can be activated by the cable manufacturer, so
that the cable manufacturer has the possibility of writing to the
memory area 24 and securing the information in the memory area 24
by write protection. In this way, the processor 12 has the
possibility of reading and outputting the information present in
the memory area 24, but the information in the memory area 24 can
no longer be overwritten by third parties.
[0204] For example, the information stored in the memory area 24
may be information concerning the kind or type of cable and/or
technical specifications of the cable.
[0205] In the memory area 26 information is stored, for example by
the purchaser of the cable, and write-protected. Here there is the
possibility for the purchaser and user of the cable to store
information concerning the installation and use of the cable and
secure it by write protection.
[0206] In the memory area 28, information can be freely written and
freely read, so that this memory area can be used for storing and
reading information during the use of the information carrier unit
in conjunction with a cable.
[0207] The exemplary embodiment of the information carrier unit 10
represented in FIG. 1 is a so-called passive information carrier
unit, and consequently does not require an energy store, in
particular an accumulator or battery, in order to interact and
exchange information with the read/write device 20.
[0208] In the case of the way in which the information carrier unit
10 is realized as represented in FIG. 2, a base 40 of said unit
extends in a longitudinal direction 41 and carries an integrated
circuit 42, which comprises the processor 12, the memory 14 and the
analog part 16, as well as conductor tracks 44, which are provided
on the base 40 and are formed, for example, for the HF range as
coil loops extending in an antenna surface 45, and form the antenna
unit 18. The conductor tracks 44 may in this case be applied to the
base 40 by means of any desired form-selective coating processes,
for example in the form of printing a conductive lacquer or a
conductive paste.
[0209] If the information carrier unit 10 is of a great extent, the
base 40 is, for example, a flexible material, in particular a
pliant material, for example a plastic strip, to which on the one
hand the conductor track 44 can be easily and permanently applied
by coating and on the other hand the integrated circuit 42 can also
be easily fixed, in particular in such a way that a permanent
electrical connection can be realized between outer connecting
points 46 of the integrated circuit 42 and the conductor tracks
44.
[0210] If the base 40 is formed as flat material, it is of
advantage if it is formed with edge regions 48 with a blunt effect
on their surroundings, in order to avoid damage to the surroundings
of the base 40 in the cable during movement of the cable. This
means in the case of a base 40 formed from a thin flat material
that it has, for example, rounded corner regions and, if possible,
also edges with a blunt effect, for example deburred edges.
[0211] In the case of a second exemplary embodiment of an
information carrier unit 10' according to the invention,
represented in FIG. 3, those elements that are identical to those
of the first exemplary embodiment are provided with the same
reference numerals, so that, with regard to the description of the
same, reference can be made to the first exemplary embodiment in
its entirety.
[0212] By contrast with the first exemplary embodiment, in the case
of the second exemplary embodiment the processor 12 also has an
associated sensor 30, enabling the processor 12 to pick up physical
variables of the cable, such as for example radiation, pressure,
temperature, tension or moisture, and for example store
corresponding values in the memory area 28.
[0213] The sensor 30 may in this case be formed in accordance with
the field of use.
[0214] For example, it is conceivable to form the sensor 30 for
measuring a pressure as a pressure-sensitive layer, it being
possible for the pressure sensitivity to take place for example by
way of a resistance measurement or, in the case of multiple layers,
a capacitive measurement.
[0215] As an alternative to this, it is, for example, conceivable,
for forming the sensor 30 as a temperature sensor, to form the
sensor as a resistor that is variable with the temperature, so that
a temperature measurement is possible by a resistance
measurement.
[0216] If the sensor 30 is formed as a tension or elongation
sensor, the sensor is formed, for example, as a strain gage, which
changes its electrical resistance in accordance with
elongation.
[0217] If, however, the sensor 30 is formed as a sensor reacting
irreversibly to a specific elongation or to a specific tension, it
is likewise possible to form the sensor as a sensor breaking an
electrical connection, for example as a wire or conductor track for
which the electrical connection is interrupted as from a specific
tension or a specific elongation, by rupturing at a predetermined
breaking point or by tearing, or goes over from a low resistance to
a high resistance.
[0218] If appropriate, however, the tension measurement or the
elongation measurement could also be realized by a capacitive
measurement.
[0219] In the case of a moisture sensor, the sensor 30 is
preferably formed as a multilayer structure which changes its
electrical resistance or its capacitance in accordance with
moisture.
[0220] Otherwise, the second exemplary embodiment according to FIG.
2 operates in the same way as the first exemplary embodiment.
[0221] If the second exemplary embodiment is realized as
represented in FIG. 4, the information carrier unit 10' also
comprises the sensor 30, which may, for example, be a radiation
sensor for all types of physical radiation, a temperature sensor, a
tension or elongation sensor or a moisture sensor, which is formed
over a large area as a layer 32 and is disposed on the base 40
along with the antenna unit 18, as represented in FIG. 4.
[0222] In the case of a variant of the second exemplary embodiment
that is represented in FIG. 5, the sensor 30 is formed as a
multilayer structure 34 and can consequently be operated with a
space-saving structure as a capacitive sensor 30. In this case,
moisture, temperature or pressure can be easily picked up in
particular on the basis of the state-dependent capacitance.
[0223] Such a sensor 30 can be easily contacted by the integrated
circuit or be formed as part of the same.
[0224] By contrast with the second exemplary embodiment, in the
case of a third exemplary embodiment 10'', represented in FIG. 6,
the analog part 16 has an associated antenna unit 18'', which has a
two-part effect, to be specific for example an antenna part 18a,
which communicates in a known way with the read/write device 20,
and an antenna part 18b, which is capable by induction of coupling
to an alternating magnetic field 31 and drawing energy from it, in
order to operate the information carrier unit 10'' independently of
the read/write device 20 with this energy drawn from the
alternating magnetic field 31.
[0225] For example, the alternating magnetic field 31 can be
produced by the leakage field of an alternating current line which
is connected, for example, to an AC voltage source with 50 Hz. It
is in this way possible to supply the information carrier unit 10''
with energy as long as the alternating field 31 exists,
irrespective of whether the read/write device 20 is intended to be
used for writing or reading information.
[0226] Supplying the information carrier unit 10'' with electrical
energy in such a way, independently of the read/write device 20, is
useful in particular if the sensor 30 is intended to be used over
relatively long time periods for picking up a physical variable
which is not intended to coincide with the time period during which
the read/write device 20 is coupled to the antenna unit 18a but to
be independent of it.
[0227] Consequently, for example, the information carrier unit 10''
can be activated by switching on the alternating magnetic field 31,
so that physical state variables can be measured on the part of the
sensor 30 and picked up by way of the processor 12, and for example
stored in the memory area 28, independently of the question as to
whether or not the read/write device 20 is coupled with the antenna
unit 18.
[0228] For example, the alternating magnetic field 31 may be
produced by the stray field of a data line, a control line, a
pulsed power line or an alternating current line, which is, for
example, connected to an AC voltage source with 50 Hz or a higher
frequency. It is in this way possible to supply the information
carrier unit 10'' with energy as long as the alternating field 31
exists, irrespective of whether the read/write device 20 is
intended to be used for writing or reading information.
[0229] The frequency of the alternating field 31 and the resonant
frequency of the antenna part 18b can be made to match each other
in such a way that the antenna part 18b is operated in resonance,
and consequently allows optimum coupling-in of energy from the
alternating field 31.
[0230] Supplying the information carrier unit 10'' with electrical
energy in such a way, independently of the read/write device 20, is
useful in particular if the sensor 30 is intended to be used over
relatively long time periods for picking up a physical state
variable which is not intended to coincide with the time period
during which the read/write device 20 is coupled to the antenna
unit 18a but to be independent of it.
[0231] Consequently, for example, the information carrier unit 10''
can be activated by switching on the alternating electromagnetic
field 31, so that physical state variables can be measured on the
part of the sensor 30 and picked up by way of the processor 12, and
for example stored in the memory area 28, independently of the
question as to whether or not the read/write device 20 is coupled
with the antenna unit 18''.
[0232] If the third exemplary embodiment is realized as represented
in FIG. 7, the sensor 30 is formed as a strain gage 36, which in
the case of this exemplary embodiment is disposed on a substrate 37
which is connected to the base 40 and can be elongated in a
longitudinal direction 38 of the strain gage 36.
[0233] In the case of this exemplary embodiment, the substrate 37
together with the strain gage 36 can be advantageously fixed on the
part to be measured or embedded in it, so that the elongation of
this part or of the surroundings of the substrate 37 is transmitted
to the substrate 37, and consequently the substrate 37 can pick up
the elongation of its surroundings and transmit it to the strain
gage 36 in an unfalsified manner.
[0234] In the case of this exemplary embodiment, the longitudinal
direction 38 runs, for example, parallel to the direction 41, which
represents a longitudinal direction of the base 40, but may also
run transversely thereto.
[0235] Consequently, provided that the strain gage 36 is fixedly
connected to a component part of the cable that can undergo
elongation, in the case of this information carrier unit 10'', it
is possible for elongations in the longitudinal direction 38 of the
strain gage 36 to be measured and to be picked up on the part of
the processor 12 on the integrated circuit 42.
[0236] An information carrier unit corresponding to the exemplary
embodiments described above can be used according to the invention
in different variants for a cable.
[0237] A first exemplary embodiment of a cable 60 according to the
invention, represented in FIG. 8, comprises an inner cable body 62,
in which a number of electrical conductor strands 64 run, the
electrical conductor strands 64 respectively comprising, for
example, a core 66 of an electrical or optical conductor, which for
its part is again insulated.
[0238] In this case, the conductor strands 64 are preferably
twisted with one another about a longitudinal axis 70 running
parallel to a longitudinal direction 69 of the cable 60, that is to
say they lie disposed about the longitudinal axis 70 and run at an
angle to a parallel to the longitudinal axis 70 that intersects the
respective conductor strand 64.
[0239] The inner cable body 62 is enclosed by a first separating
layer 72, which is formed, for example, as a protective film and
completely encloses the inner cable body 62 in a circumferential
direction. For example, the separating layer 72 is wound in the
form of one or more strips 76 around the inner cable body 62 and
encloses the latter completely in the circumferential direction
74.
[0240] The separating layer 72 thereby separates the inner cable
body 62 from a shielding 80, which likewise encloses the inner
cable body 62 and the separating layer 72 completely in the
circumferential direction 74, and consequently protects the inner
cable body 62, in particular the conductor strands 64, from
electromagnetic interference, and on the other hand also prevents
electromagnetic emissions from it.
[0241] In the case of this exemplary embodiment, the shielding 80
is covered by a second separating layer 82, which likewise again
completely encloses the screen 80. The second separating layer 82
may in this case be formed as a filler tape which runs in the
direction of the longitudinal axis 70 and encloses the shielding
80, or likewise by strips 86 wound around the shielding 80, for
example in an overlapping manner, for example formed from a
continuous material or some other material.
[0242] The second separating layer 82 is once again enclosed by an
outer cable sheath 90, which is preferably produced during the
production of the cable 60 by extrusion and likewise completely
encloses the second separating layer 82 in the circumferential
direction 76. The outer cable sheath 90 usually adheres to the
second separating layer 82.
[0243] The outer cable sheath 90 for its part forms an outer sheath
surface 92 of the cable, defining the outer contour of the cable
60.
[0244] In the case of the first exemplary embodiment of a cable 60
according to the invention, represented in FIG. 8, one of the
strips 86 carries, for example, the information carrier unit 10
according to the first exemplary embodiment described, the
information carrier unit 10, as represented in FIG. 9, being
disposed on the strip 86, which in this case represents a carrier
strip for the information carrier unit 10. When the cable 60
according to the invention is produced, one or more information
carrier units 10 are also incorporated in the cable with the strip
86 by winding said strip 86 around the shielding 80.
[0245] For example, the base 40 of the information carrier unit 10
is then fixed on the strip 86 by means of a flexible and elastic
adhesive layer 100.
[0246] For the communication between the read/write device 20 and
the information carrier unit 10, there forms in the HF range a
magnetic field 102 (FIG. 10), which couples the antenna unit 19 of
the read/write device 20 and the antenna unit 18 of the
identification unit 10 with each other. To avoid eddy currents
caused by this electromagnetic field 102 in the shield 80 by field
induction and the opposing field building up as a result, which
weakens the electromagnetic field 102, provided between the base 40
and the adhesive layer 100 is a magnetic-field-concentrating layer
104, which concentrates the magnetic field 102 that passes through
the antenna surface 45, and consequently also the antenna unit 18,
and thereby keeps it away from the shielding 80, so that the
antenna unit 19 of the read/write device 20 and the antenna unit 18
of the information carrier unit 10 can be coupled by way of the
electromagnetic field 102 with a sufficiently great degree of
coupling, and consequently make communication between the
read/write device 20 and the identification unit 10 possible to an
extent which corresponds approximately or virtually to the
conditions of a cable without such shielding 80.
[0247] In this case, the magnetic-field-concentrating layer 104 is
formed as a layer in which magnetically conductive particles 106
are disposed, embedded in an electrically insulating embedding
material 108, for example a resin or plastics material.
[0248] Such magnetically conductive particles 106 are, for example,
particles of ferrite, in particular magnetite, which are
electrically nonconductive, or of metal alloys, which may be
electrically conductive. The particles have, for example, a
particle size in the range between approximately 1 .mu.m and
approximately 50 .mu.m, still better in the range between
approximately 2 .mu.m and approximately 20 .mu.m.
[0249] The magnetic-field-concentrating layer 104, which extends in
an area of extent 110 running approximately parallel to the antenna
surface 45, provides the possibility of allowing a magnetic flux in
the direction of the area of extent 110 within the
magnetic-field-concentrating layer 104, which in turn makes a
sufficiently great magnetic flux through the antenna surface 45
possible without the electromagnetic shielding effect of the
shielding 80 having a disturbing influence, that is to say an
influence reducing the magnetic flux through the antenna unit 18,
since the magnetic-field-concentrating layer 104 for its part
shields the shielding 80 substantially completely from the magnetic
flux produced by the antenna unit 19 of the read/write device 20
and directs it in a substantially concentrated form in the
magnetic-field-concentrating layer 104.
[0250] Furthermore, in the case of this exemplary embodiment, the
base 40 is produced from an electrically inert material, so that
the base 40 has no influence on the magnetic field 102.
[0251] In the case of this exemplary embodiment, on account of the
shape of the cable 60, the antenna surface 45 is usually a surface
which runs in an approximately cylindrical manner with respect to
the longitudinal axis 70, the cylindrical shape not necessarily
having to be a circular cross-sectional shape, but may also
comprise other cross-sectional shapes, such as for example an oval
cross-sectional shape.
[0252] In the same way, the area of extent 110 is also a surface
which is likewise approximately cylindrical with respect to the
longitudinal axis 70 of the cable 60, the area of extent 110 and
the antenna surface 45 preferably running at a substantially
constant spacing from each other and consequently in each case
having a substantially similar cross-sectional shape.
[0253] In the case of a second exemplary embodiment of a cable 60'
according to the invention, represented in FIG. 11, the second
separating layer 82' is not formed by strips 86 but by a strip 87
which wraps around the shielding 80 completely like a filler tape,
extends substantially parallel to the longitudinal axis 70 and the
edges 88a and 88b of which approximately abut each other or
overlap.
[0254] In this case, the identification unit 10, as represented in
FIG. 11, may extend or be aligned with the longitudinal direction
41 of the base 40 approximately parallel to the longitudinal axis
70, the identification unit 10 being disposed and held on the
separating layer in the same way as in the case of the first
exemplary embodiment, as represented in FIG. 12.
[0255] Otherwise, there is likewise a magnetic-field-concentrating
layer 104, which acts in the same way as in the case of the first
exemplary embodiment.
[0256] By contrast with the first and second exemplary embodiments;
in the case of a third exemplary embodiment of a cable 60''
according to the invention, represented in FIG. 13, the separating
layer 72' is not formed as a film but is formed by an inner sheath
72', which is extruded onto the inner cable body 62 and encloses it
over its complete area.
[0257] Lying on this inner sheath 72' there is then the shielding
80, which is formed in the same way as in the case of the first
exemplary embodiment, and the shielding 80 is again surrounded by a
second separating layer 82, which is likewise formed in the same
way as in the case of the first exemplary embodiment, the
identification unit 10, which is also formed in the same way as in
the case of the first exemplary embodiment, being disposed on one
of the strips 86 of the second separating layer 82, for example in
a manner according to the first exemplary embodiment.
[0258] In the case of a fourth exemplary embodiment of a cable
60''' according to the invention, represented in FIG. 14, the
structure with respect to the inner cable body 62 and the first
separating layer 72 is identical to that of the first exemplary
embodiment, for example. However, the shielding 80 is enclosed by
an intermediate sheath 120, which is extruded onto the shielding 80
and consequently likewise encloses the latter over its complete
area. The intermediate sheath 120 is then for its part once again
enclosed by the outer cable sheath 90.
[0259] In the case of highly flexible cables, however, the second
separating layer 82 may also be provided between the shielding 80
and the intermediate sheath 120.
[0260] In the case of this fourth exemplary embodiment, the
information carrier unit 10 in this case is on the intermediate
sheath 120, as represented in FIG. 14 and FIG. 15, which sheath
encloses the shielding 80 completely, as represented in FIG.
15.
[0261] In the case of this exemplary embodiment, the intermediate
sheath 120 preferably comprises a magnetic-field-concentrating
layer 124, the magnetic-field-concentrating layer 124 being
obtainable, for example, by embedding magnetically conductive
particles 106 in a surface region 122 of the material of the
intermediate sheath 120 that faces the shielding 80, this being
possible by dusting of the surface of the shielding 80 before the
extrusion of the intermediate sheath 120, by incorporating the
magnetically conductive particles 106 into the surface material
region 122 that is in the softened state during the extrusion of
the intermediate sheath 120.
[0262] Such an intermediate sheath 120 enclosing a
magnetic-field-concentrating layer 124 has the overall effect of
giving the cable 60''' improved properties, since it improves the
shielding effect for electromagnetic radiation that is brought
about by the electrical shielding 82 for the magnetic field
component also.
[0263] At the same time, the magnetic-field-concentrating layer 124
of the intermediate sheath 120 serves for guiding the magnetic
field 102, which passes through the antenna surface 45 and serves
for the coupling between the antenna unit 19 of the read/write
device 20 and the antenna unit 18 of the identification unit 10, in
the same way as described for example in conjunction with the first
exemplary embodiment of the cable according to the invention, but
with the difference that in this case the
magnetic-field-concentrating layer 124 extends over the entire
cable in the direction of the longitudinal axis 70 and also
completely encloses the inner cable body 62.
[0264] As an alternative to this, however, it is also conceivable
to apply a magnetic field-concentrating layer 124 in a merely
locally limited manner, by dusting or powdering the still soft
material 122 of the shielding 80, to be specific in the region in
which placement of the identification unit 10 is intended, so that
a lower-cost solution is available on account of the saving in
magnetically conductive particles 106, in particular in all those
cases in which a complete magnetic-field-concentrating layer 124
surrounding the inner cable body 62 does not offer any
advantages.
[0265] In the case of this exemplary embodiment, the information
carrier unit 10 is, for example, likewise placed with the base 40
onto the intermediate sheath 120, for example in the region of the
surface 126 facing away from the inner cable body 62, and, for
example, adhesively attached by an adhesive layer 100.
[0266] As represented in FIG. 15, the outer cable sheath 90 covers
the inner cable sheath 120 in the region of its surface 126 and
also in this case embeds the information carrier unit 10, so that
the information carrier unit is securely fixed in the cable
60'''.
[0267] By contrast with the fourth exemplary embodiment, in the
case of a fifth exemplary embodiment of a cable 60'''' according to
the invention, represented in FIG. 16, the
magnetic-field-concentrating layer 124' is disposed on a side of
the intermediate sheath 120 that is facing away from the shielding
80 and is produced by dusting, powdering or sprinkling the material
122' of the intermediate sheath 120 that is still soft, or softened
by subsequent heating, after extrusion of said sheath, so that the
base 40 of the information carrier unit 10 is placed onto the
magnetic-field-concentrating layer 124' and, for example, fixed by
the adhesive layer 100.
[0268] In the case of a sixth exemplary embodiment of a cable 60
according to the invention, represented in FIG. 17, the structure
corresponds in principle to the fourth exemplary embodiment of the
cable 60''' according to the invention, but in the case of this
exemplary embodiment a separating layer 82 is provided between the
shielding 80 and the intermediate sheath 120 in order to give the
cable the greatest possible bendability or flexibility and the
information carrier unit 10 is embedded in the intermediate sheath
120.
[0269] Furthermore, the intermediate sheath 120 is not itself
provided with the magnetic-field-concentrating layer 124, but the
base 40 carries the magnetic-field-concentrating layer 104 on its
side facing the inner cable body 62, as has been described in
conjunction with the first or second exemplary embodiment.
[0270] Then, the conductor tracks 44 and the integrated circuit 42
are disposed on the base 40 in a way corresponding to the exemplary
embodiments previously described.
[0271] Preferably, the entire information carrier unit 10 is
substantially embedded in the intermediate sheath 120, so that the
conductor tracks 44 and the integrated circuit 42 on the base 40
also protrude only partially above the surface 126 of the
intermediate sheath 120, which for its part is once again covered
by the outer cable sheath 90, so that the outer cable sheath 90
completely surrounds the entire intermediate sheath 120 in the
manner described.
[0272] In the case of a seventh exemplary embodiment of a cable 60
according to the invention, represented in FIG. 18, the structure
of the cable itself is identical in principle to that of the fourth
and fifth exemplary embodiments, but with the difference that in
the case of this exemplary embodiment, the antenna unit 18 is
formed for the UHF range, and consequently the conductor tracks 44
merely represent a so-called dipole antenna.
[0273] In the UHF range, the disturbance of the electromagnetic
field 102 coupling the antenna unit 19 of the read/write device 20
and the antenna unit 18 of the information carrier unit 10 is small
if the antenna surface 45 is at a sufficiently great distance A
from the shielding 80, the distance in this case being at least
approximately 1.5 mm, still better at least 2 mm.
[0274] For this reason, no magnetic-field-concentrating layer is
required in the case of this exemplary embodiment if, as
represented in FIG. 18, the information carrier unit 10 is on a
spacing element 132, which together with the second separating
layer 82, the adhesive layer 100 and the base 40 forms a
sufficiently thick spacing layer between the shielding and the
antenna unit 18.
[0275] In the case of an eighth exemplary embodiment of a cable
60''''''' according to the invention, represented in FIG. 19, to
achieve a sufficiently thick spacing layer for the operation of the
information carrier unit 10 in the UHF range, it is provided that
the information carrier unit 10 is at least partly embedded in the
intermediate sheath 120, and consequently the antenna surface 45
can be disposed at a sufficient distance from the shielding 80, the
material of the intermediate sheath 120 and the material of the
separating layer 82 not substantially impairing the electromagnetic
field 134, that is to say said materials are electromagnetically
inert, so that the electromagnetic field 134 can also extend
between the antenna surface 45 and the shielding 80 to the extent
necessary to achieve sufficiently good coupling between the antenna
unit 19 of the read/write device 20 and the antenna unit 18.
[0276] Otherwise, in the case of the second to eighth exemplary
embodiments, all the parts that are identical to those of the
previous exemplary embodiments are provided with the same reference
numerals, so that, with regard to the description and function of
these parts in each exemplary embodiment, reference is made to the
previous exemplary embodiments.
* * * * *